What
is sewage and how does it get into marine recreational water?Sewage
is used water that often contains human waste (feces and urine). It
is usually pumped through a network of pipes from homes and businesses
to a sewage treatment plant. Sometimes large sewage lines break and
the contents leak into marine recreational waters and beaches.

What
organisms can live in sewage-contaminated water?A
variety of organisms live in the human gastrointestinal tract. These
organisms, including bacteria, viruses, and parasites, end up in human
waste. Many of these organisms can be transmitted to other humans and
animals, including marine organisms like shellfish, through contact
with sewage-contaminated water.

What are the possible routes of exposure?There
are many routes of human exposure to the organisms in sewage-contaminated
water:

oral
- drinking contaminated water or eating contaminated seafooddermal - getting contaminated
water on your skin and in open cuts or rashesaerosol
- inhaling water droplets such as those from breaking waves.

What
are the possible diseases caused by exposure to sewage-contaminated
water?The
most commonly reported illness associated with oral exposure to contaminated
water is generally called gastro-enteritis.
Gastro-enteritis is an infection of the gastrointestinal tract. It can
result from aerosol exposure to contaminated water, too. Oral exposure
to sewage-contaminated water can also cause hepatitis,
an infection of the liver. Dermal exposure to sewage-contaminated water
often results in the infection of
open cuts or rashes.

What
are the symptoms of diseases caused by exposure to sewage-contaminated
water?Gastro-enteritis
can affect different parts or the whole of the gastro-intestinal tract.
Symptoms of gastro-enteritis include vomiting, pain in the abdomen,
and/or diarrhea. Sometimes gastro-enteritis is accompanied by a fever.
The illness can cause severe dehydration (loss of water and electrolytes)
due to the vomiting and/or diarrhea. This is especially common in little
children or persons who are already sick with other conditions.

Hepatitis
can look exactly like gastro-enteritis. Severe cases cause people's
skin to become yellow, or jaundiced, because the liver is not able to
clear out its own bile. Bile contains the liver's waste products.

Infected
cuts or rashes look swollen, red, and may have a thick yellowish
discharge called pus. There is usually a lot of pain at the site of
the rash or cut. Sometimes the infection causes a fever. Of note, eyes
and ears can be infected in the same way.

What is the risk to people from using sewage-contaminated recreational
waters?Pruss
(1998) reviewed all significant existing studies of the effects of exposure
to sewage-contaminated recreational water on human health. She found
that most of these studies reported a dose-related increase of health
risk in swimmers with an increase in the indicator bacteria counts in
the recreational water. That means as the number of indicator bacteria
in recreational water increased, so did the risk for sickness in humans
using it. The indicator organisms that correlated best with the risk
of sickness in humans were enterococci/fecal streptococci in marine
and freshwater, and E. coli in freshwater. In both marine and freshwater,
the increased risk of gastrointestinal illness was associated with water
quality values ranging from only a few indicator counts/100 ml to about
30-indicator counts/100 ml. These values are low compared to water qualities
frequently encountered in coastal recreational waters. Of note, the
majority of these studies were conducted in the US and UK, with few
studies evaluated in tropical marine recreational waters.

Haile et
al. (1999), among others, evaluated the risk of reported gastrointestinal
illness and other symptoms with respect to reported distance from storm
drains with untreated run off in Los Angeles County, CA. Over 22,000
persons were interviewed concerning their health nine days after they
exposed their faces to recreational beach waters. An increased risk
of adverse health outcomes was associated with swimming in ocean water
contaminated by untreated urban runoff. There was a significant dose
response relationship. That is to say the closer a person swam to a
storm drain, the greater their risk of having adverse health outcomes.

How
do I know if the marine water is contaminated?Traditionally,
the quality of marine coastal water used for recreational purposes has
been regulated by measuring concentrations of indicator microbes. The
microbes monitored are those typically found in high concentrations
in human feces. An elevated concentration of these microbes in coastal
water would indicate that the water has been contaminated by human waste
and is unsafe for recreational use.

How can I prevent sickness from sewage-contaminated marine water?The
easiest way to prevent sickness from sewage-contaminated marine water
is to avoid exposure. Do not get the contaminated water on your skin,
in your eyes or ears, or in your mouth. That means no swimming in contaminated
water or eating raw or partially cooked food that came from sewage-contaminated
water.